package com.heoma.kafka.sample;

import org.apache.kafka.clients.consumer.*;
import org.apache.kafka.clients.producer.ProducerConfig;
import org.apache.kafka.common.TopicPartition;

import java.time.Duration;
import java.util.Collections;
import java.util.Map;
import java.util.Properties;

/**
 * 消息消费者
 */
public class ConsumerQuickStart {
    public static void main(String[] args) {

        //kafka的连接配置信息
        Properties prop = new Properties();
        //连接地址
        prop.put(ConsumerConfig.BOOTSTRAP_SERVERS_CONFIG, "192.168.86.129:9092");
        //消费者组
        prop.put(ConsumerConfig.GROUP_ID_CONFIG, "group1");
        //手动提交偏移量
        prop.put(ConsumerConfig.ENABLE_AUTO_COMMIT_CONFIG, false);
        //key的序列化
        prop.put(ConsumerConfig.KEY_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
        //value的序列化
        prop.put(ConsumerConfig.VALUE_DESERIALIZER_CLASS_CONFIG, "org.apache.kafka.common.serialization.StringDeserializer");
        //创建消费者对象
        KafkaConsumer<String, String> consumer = new KafkaConsumer<>(prop);
        //订阅主题
        consumer.subscribe(Collections.singletonList("topic-frist"));
        //拉取消息
        //当前线程一直处于监听状态
        while (true) {
            //4.获取消息
            ConsumerRecords<String, String> consumerRecords = consumer.poll(Duration.ofMillis(1000));
            for (ConsumerRecord<String, String> consumerRecord : consumerRecords) {
                System.out.println(consumerRecord.key());
                System.out.println(consumerRecord.value());
                //偏移量 记录消费到了什么位置
                System.out.println(consumerRecord.offset());

                //异步提交偏移量
                consumer.commitAsync(new OffsetCommitCallback() {
                    @Override
                    public void onComplete(Map<TopicPartition, OffsetAndMetadata> map, Exception e) {
                        if (e != null) {
                            System.out.println("记录错误的提交偏移量" + map + "异常信息" + e);
                        }
                    }
                });
            }
        }
    }
}
